Method for duplicating the dye of an original on a dye carrier



y 3, 1962 E. ROHNER 3,042,476

METHOD FOR DUPLICATING THE DYE OF AN ORIGINAL ON A, DYE CARRIER FiledMarch 21, 1960 5 Sheets-Sheet 1 Fig. 7 404 640 700 I I l I I an I I I II 60 I I l I I I 4 I 2 25 I 7 I27 I R% 1 I I I I I I I l y I 700 400 500600 404 510 Fig 2 640 100 I I I I I I I I I I I 80 I I I 0,01% I I I I60 I 40 W l I I i I 10 N I O 9% I I I I a I A IN VEA/TOR ERNST ROhA/EIRWM {M JMML July 3, 1962 E. ROHNER 3,042,476

METHOD FOR DUPLIGATING THE DYE OF AN ORIGINAL ON A DYE CARRIER FiledMarch 21, 1960 5 Sheets-Sheet 2 404 510 3 640 100 I I i I I I I so i i iC /L 60 I 001% I I c I I i I I 40 I 0I 0/o C i 5% I I Fig. 4 494 s o 610I I I I I I I I 80 i i I i v I l I i l I 40 I i I b I 1.0% I I I I b I-r-" I I I 400 500 600 700 MM] INI/EA/TOR ERNST R (DIM/ER A? WM myd-July 3, 1962 E. ROHNER METHOD FOR DUPLICATING THE DYE OF AN ORIGINAL ONA DYE CARRIER 5 Sheets-Sheet 3 Filed March 21, 1960 mos Q INVEA/TORIIII.

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July 3., 1962 E. ROHNER 3,042,476

METHOD FOR DUPLICATING THE DYE OF AN ORIGINAL on A DYE CARRIER FiledMarch 21, 1960 5 Sheets-Sheet 4 1 3 S g g 8 8 2 m 5 & n n r Fig 6 N Q QQ o 0 Q Q Q i R a s lA/ws/vroR ER/VST ROHA/ER y 3, 1962 E. ROHNER3,042,476

METHOD FOR DUPLICATING THE DYE OF AN ORIGINAL ON A DYE CARRIER FiledMarch 21, 1960 5 Sheets-Sheet 5 Fig- 7 lOLOOOG 1 a l/VVEA TM ERA/$1"RO/fA/ER myj United States i atent @ii'ice 3,042,475 Patented July 3,1962 3,042,476 METHGD FGR DUPLICATING THE DYE OF AN QRIGINAL ON A DYECARREER Ernst Rohner, Zurich, Switzerland, assignor to Pretema A.G.,Zurich, Switzerland Filed Mar. 21, I060, Ser. No. 16,485 Claimspriority, application Germany Mar. 24, 1959 3 Claims. (Cl. 8-25) It isknown that when duplicating the dye mixture of an original, therequisite recipes are determined by subjective, visual methods. In sucha method, mixing preferably proceeds from a known recipe which isvisually as similar to the original as possible. The desired dye recipewhich most closely approximates the original, is obtained by this methodafter a time-consuming series of color corrections.

It is further known that the requisite dye recipes can be determinedgraphically or computationally by methods based on the Kubelka-Munk law.This law is, however, of only limited validity when applied to practicaldyeing processes, since the factors which greatly influence the variablecharacteristics of the various dye carriers, for example, textiles,plastics, paper, etc., are not considered in the computations. Inaddition, the variations of the conditions in dyeing technology cannotbe taken into consideration with sufiicient accuracy. Both theseconsiderations, as well as the considerable amount of computationnecessary, make the practicalutility of these methods questionable, sothat a successful production, which more or less resembles the original,is achieved only after tedious correction by highly skilled personnel.

The method of the present invention avoids the disadvantages of thevisual as well as of the graphic and computational methods of recipedetermination for duplication of dye exemplars.

The method according to present invention comprises applying a number ofprimary-color dyestuffs, in a plurality of dyestufi concentrations tothe same dye carrier to be dyed, determining from these samples thespectral re-emission curves, determining the spectral emission curve ofthe original dye mixture, selecting from the spectral re-emission curveof the primary-color dyes the number of wave-lengths corresponding tothe number of the primary-color dyes, wherein the ratio of there-emission of one primary-color dye to the ratios of the reemissions ofthe other primary-color dyes is a minimum, tracing graphically for thesewave lengths the re-emission values of the primary-color dyes as afunction of the dye-bath concentration, determining from these graphs,the bath concentration of the individual dye components of the dyemixture at the re-ernission values corresponding to the wave-lengths ofthe original dye mixture, mixing the dye components in the determinedconcentration, and dyeing the dye carrier with this mixture of dyes.

In the novel method of the present invention, the dye recipes can bedetermined with a high degree of accuracy Within a few minutes, and thesubsequent dyeing process can be considerably shortened as compared withpreviously known methods. This results in a better utilization of thedyeing machines and a correspondingly increased productivity.

The invention will be more fully described with reference to theaccompanying drawings showing diagrams which are required for carryingout the individual steps of the present invention.

FIGURE 1 shows the spectral re-emission curves of the original dye andthe duplicate, drawn as function of the wavelength.

FIGURES 2, 3 and 4 show each the spectral re-ernission curves for aprimary-color dye at various dyestufi concentrations.

FIGURES 5, 6 and 7 show the concentration curves of the threeprimary-color dyes, each at a chosen wavelength.

The following example will be based on the assumption that the originaldyestuff which is to be duplicated contains the primary-color dyes,blue, scarlet, and yellow. The spectral re-emission curve No. 1 ofFIGURE 1 is known. The above-mentioned primary-color dyes are firstapplied to the dyeable dye carrier material in various concentrations(in the example of the present invention, according to FIGS. 2 to 4incl., in concentrations of 0.01%, 0.1% and 1.0%). It is advantageous tocarry out this dyeing operation within a concentration range of 0.005%to 2.0%. From these samples, the curve of the re-emission, R, inpercent, carried over the wave-length of the spectral re-emission curve(FIGS. 2- 4 incl.) can be determined, whereby FIG. 2 shows there-emission curves a for the blue primarycolor dyestufi, FIG. 3 showsthe re-emission curves c for the primarycolor dyestuff scarlet, and FIG.4 the re-emission curves b for the primary-color dyestufif yellow. Fromthese emission curves, a, b, c, a number of Wavelengths are chosen whichrepresent the number of these basic colors,

and by comparison of these three graphic representations,

2 to 4 incl., those Wavelengths are chosen, in which the proportion ofone primary-color dye to the other primarycolor dyes is at a minimum.:It is evident from FIGS. 2 to 4 incl. that the re-emission of theprimary-color dyestuff, blue, is at a minimum with respect. to thereemissions of the other two primary-color dyestuffs, yellow and scarletat A 640 m It is to be noted, that the choice does not depend on thesmallest absolute value of the blue primary-color dyestuff (this isapproximately at A 600 m but upon the ratio of this re-emission to there-emissions of the other dyestufis. It may also be seen from FIGS. 2-4incl. that the minimum ratio for the primary-color dyestuff scarlet isat A 510 m and for the primary-color dyestufl yellow, at A 404 m Now thethree wave-lengths of the re-emission values of the three basic dyes,chosen by the above method, can be represented graphically as a functionof the dyestufi concentration, K. This can be accomplished mostadvantageously by logarithmic means, as in the illustrated example.FIGS. 5, 6 and 7 show the concentration curves A, for blue, B, foryellow, and C for scarlet at the respective wave-lengths A 640 rn A 404m and A 510 m The recipe for the duplicating dye mixture can now bedetermined from these concentration curves.

According to the re-emission curve of the original dye, as shown in FIG.1, a total re-emission of 127% is required at wave-length A 640 m Since,as shown in FIGS. 2-4 incl., the primary-color, blue, is the soledecisive factor, the concentration K which represents a re-emission Requal to 27% is sought in curve A of FIG. 5, and yields a concentrationfor blue of 0.058%. According to the curve 1 of FIG. 1, the dye samplehas a re-emission value at wave-length A 510 m of 37.5%, and as shown byFIGS. 2-4 incl., the prime factor in the re-ernission at thiswave-length is the primary color, scarlet. It must first be assumed thatthe re-emission value of 37.5% is produced by the dyestuff scarletalone, and on this assumption, the concentration of scarlet, K, of0.035, representing the re-emission value, R, of 37.5% is found in curveC of FIG. 6.

Since, however, according to FIG. 6 the primary-color dyestufE blue,actually has a considerable influence on the real re-emission of theduplicating dye in the 510 m range, the value K=0.035% for the scarletdye concentration must be corrected accordingly. The previouslydetermined dyestulf concentration. 0.05 8% for blue (curve A), gives, asshown by FIG. 6, a corresponding dyestufi concentration for scarlet of0.029%. For scarkkw l let, therefore, only the difference in theconcentrations at wave-length 510 m is required, i.e. 0.006%, in orderto obtain the desired emission value of 37.5%. The determination of therequisite dyestuff concentration at wave-length 404 m can beaccomplishedin an analogous manner. According to curve 1, FIG. 1, the originaldyestuif requires a re-ernission value of 45% at this wavelength. This,according to FIG. 7 (curve B), represents a concentration of thedyestufi? of 0.0155 for the primary-color yellow. It can further bedetermined from FIG. 7, that the wave-length of 404 my, and the knownblue dyestufi concentration of 0.058% represents a yellow dyestuflconcentration (curve B) of 0.0095%. The influence of the known scarletdyestuff concentration (curve C) of 0.006% at wave-length 484 mg is verysmall, and is, as FIG. 7 indicates, at the most or the order of 0.001%.The corrected dyestuif concentration for yellow can be derived thereforefrom the difference between the total theoretical concentration ofyellow, and the concentrations due to the influence of the blue andscarlet. This is, 0.01550.0095-0.001=0.005%.

Since the influence of the primary-color dyestuff yellow was ignored inthe determination of the concentration of the scarlet dyestuff, a checkmust be made after the dyestuff concentration of the yellow has beendetermined, to ascertain if disregarding the influence of the yellow onthe scarlet was permissible. In the above example, as shown by FIG. 6,this was the case. Should the influence of the yellow dyestuficoncentration be significant, then the concentration which was firstfound.

for scarlet must be corrected in a known manner, according to FIG. 6,and this constitutes a check on the concentration of the yellowdyestuif.

A second correction of the concentration of the yellow dyestuif bycorrection of the concentration of the scarlet dyestufl, is, howeversuperfluous in most cases in practice, a fact which can be immediatelyconcluded from FIG. 7.

The recipe for the duplicate dyestufi for the above example accordinglyis as follows:

Percent Dyestutf concentration for blue 0.058 Dyestufi concentration forscarlet 0.006 Dyestutf concentration for yellow 0.005

The spectral re-emission curve of the duplicate dye of this recipe isshown by curve 2 of FIG. 1. The correspondence is good, and lies withinthe range of practical tolerance. The slight deviations derive from acertain mutual influence whichthe used dyestuflfs have upon each other.The deviations can, if necessary, be eliminated by means of a singlecorrection, utilizing the above described methods based on FIGS. to 7.

A test dyeing is carried out with the primary-color dyes, and the curvesof the primary dyes will only be correct if each of the dyes have beencompletely taken up by the dye carrier material. In dyeing the dyecarrier with the dye mixture, on the other hand, this is not necessarilythe case, and much depends upon the nature of the material of which thedye carrier is made. Thus, for instance, wool absorbs considerably moredyestuif than do synthetic fibers. With the latter material, a somewhatlighter coloration is obtained, as is evident in curve 2 of FIG. 1.Thus, for example, a sample requires a re-emission of 37.5% (curve 1) atwave-length 510 m while the duplicate dyeing, as shown in curve 2, givesa re-emission of 40% at this wave-length. From FIG. 6, it is evidentthat a re-emission of 40% (instead of 37.5%) would give a scarletconcentration of only 0.03, instead of 0.035. The diflerence, thereforeis no 4 longer 0.006%, but 0.011% for the corrected scarletconcentration. In this manner, a corrected recipe is obtained which nowduplicates the dyeing characteristics of the original dye withconsiderably more accuracy. A single test dyeing with subsequentcorrection is sufiicient in all cases occurring in practice, thuseliminating the numerous test dyeings and corrections by skilledpersonnel which were necessary until now, saving labor, material andpermitting the employment of personnel of a lesser degree of skill,since the duplication of a color no longer depends upon the skill of thepersons who proceed to the correction of the test dyeings.

I claim:

1. A method for duplicating a master dyeing obtained from :an originaldye mixture on a given dye carrier mamaterial, which comprises (l)dyeing samples of said dye carrier material, each with one of adetermined number of different primary-color dyestuffs in one of adetermined number of difierent dyestufi concentrations, wherebyindividual samples of each primary-color dyestulf in each dyestuficoncentration is obtained;

(2) measuring and plotting against wavelength the spectral re-emissionvalues of each of these samples;

(3) measuring and plotting against wavelengths the spectral emissionvalues of said master dyeing;

(4) plotting against dyestufi concentration those reernission valuestaken from the curves obtained by (2) which correspond to thewavelengths for which the re-emission ratio of each primary colorproporportion-ate to the remaining primary colors has a minimum value;

(5) preparing a dyebath of :a mixture of all of said primary colordyestuffs containing each dyestuff in that concentration whichcorresponds in the curves obtained under (4) to the re-emission valuetaken from the curve obtained under (3) for the wavelength correspondingto the said re-emission minimum ratio of the respective primary color,and

(6) dyeing goods of the said dye carrier material, thereby obtainingdyeings substantially duplicating said master dyeing.

2. The method claimed in claim 1, wherein there is first prepared a bathof the primary-color dyestutf of that concentration which corresponds inthe curve obtained under 4) to a re-emission value which is closest, forthe wavelength of that color, to the re-emission value her the samewavelength in the curve obtained under (3), and adjusting theconcentration of each of the other primaryco-lor dyes with respect tothe proportion of the re-emission values of the other primary-color dyesat their respective wavelengths, thereby attaining concentrationscorresponding substantially entirely to the re-emission values of thecurve under (3).

3. A method as claimed in claim 1, in which after determination of theprimary-color dyestufi concentnations, a test dyeing is carried out, thetest re-emission curve is determined and plotted, and then theconcentrations of the primary-color dyebaths are adjusted in accordancewith the diflerences in the re-emission values between said testre-emission curve and the re-emission curve of the original dyestufi'mixture, at the wavelengths at which they were determined.

References Cited in the file of this patent FOREIGN PATENTS 506,258Great Britain May 24, 1939 620,768 Great Britain Mar. 30, 1949

1. A METHOD FOR DUPLICATING A MASTER DYEING OBTAINED FROM AN ORIGINALDYE MIXTURE ON A GIVEN DYE CARRIER MAMATERIAL, WHICH COMPRISES (1)DYEING SAMPLES OF SAID DYE CARRIER MATERIAL, EACH WITH ONE OF ADETERMINED NUMBER OF DIFFERENT PRIMARY-COLOR DYESTUFFS IN ONE OF ADETERMINED NUMBER OF DIFFERENT DYESTUFF CONCENTRATIONS, WHEREBYINDIVIDUAL SAMPLES OF EACH PRIMARY-COLOR DYESTUFF IN EACH DYESTUFFCONCENTRATION IS OBTAINED; (2) MEASURING AND PLOTTING AGAINST WAVELENGTHTHE SPECTRAL RE-EMISSION VALUES OF EACH OF THESE SAMPLES; (3) MEASURINGAND PLOTTING AGAINST WAVELENGTHS THE SPECTRAL EMISSION VALUES OF SAIDMASTER DYEING; (4) PLOTTING AGAINST DYESTUFF CONCENTRATION THOSEREEMISSION VALUES TAKEN FROM THE CURVES OBTAINED BY (2) WHICH CORRESPONDTO THE WAVELENGTHS FOR WHICH THE RE-EMISSION RATIO OF EACH PRIMARY COLORPROPORPORTIONATE TO THE REMAINING PRIMARY COLORS HAS A MINIMUM VALUE;(5) PREPARING A DYEBATH OF A MIXTURE OF ALL OF SAID PRIMARY-COLORDYESTUFFS CONTAINING EACH DYESTUFF IN THAT CONCENTRATION WHICHCORRESPONDS IN THE CURVES OBTAINED UNDER (4) TO THE RE-EMISSION VALUETAKEN FROM THE CURVE OBTAINED UNDER (3) FOR THE WAVELENGTH CORRESPONDINGTO THE SAID RE-EMISSION MINIMUM RATIO OF THE RESPECTIVE PRIMARY COLOR,AND (6) DYEING GOODS OF THE SAID DYE CARRIER MATERIAL, THEREBY OBTAININGDYEINGS SUBSTANTIALLY DUPLICATING SAID MASTER DYEING.